The United States has targeted a lot of rogues and their regimes in recent decades: Muammar Gadhafi, Saddam Hussein, Slobodan Milosevic, Mohamed Farrah Aidid, Manuel Noriega and the Taliban.

As a general rule over the last 100 years, any time the U.S. has bombed or intervened and then abruptly left the targeted country, chaos has followed. But when America has followed up its use of force with unpopular peacekeeping, sometimes American interventions have led to something better.

The belated entry of the United States into World War I saved the sinking Allied cause in 1917. Yet after the November 1918 armistice, the United States abruptly went home, washed its hands of Europe’s perennial squabbling and disarmed. A far bloodier World War II followed just two decades later.

It may have been wise or foolish for Presidents John F. Kennedy and Lyndon Johnson to have intervened in Vietnam in 1963-1964 to try to save the beleaguered non-communist south. But after 10 years of hard fighting and a costly stalemate, it was nihilistic for America to abandon a viable South Vietnam to invading communist North Vietnam. Re-education camps, mass executions and boat people followed — along with more than 40 years of communist oppression.

The current presidential candidates are refighting the Iraq war of 2003. Yet the critical question 13 years later is not so much whether the United States should or should not have removed the genocidal Saddam Hussein, but whether our costly efforts at reconstruction ever offered any hope of a stable Iraq.

By 2011, Iraq certainly seemed viable. Only a few dozen American peacekeepers were killed in Iraq in 2011 — a total comparable to the number of U.S. soldiers who die in accidents in an average month.

The complete withdrawal of all U.S. troops in December 2011 abruptly turned what President Barack Obama had dubbed a “sovereign, stable and self-reliant” Iraq — and what Vice President Joe Biden had called one of the administration’s “greatest achievements” — into a nightmarish wasteland.

Hillary Clinton bragged of the 2011 airstrikes in Libya and the eventual death of Gadhafi: “We came, we saw, he died.”

But destroying Gadhafi’s forces from the air and then abandoning Libya to terrorists and criminals only created an Islamic State recruiting ground. The Benghazi disaster was the nearly inevitable result of washing our hands of the disorder that we had helped to create.

In contrast, when the United States did not pack up and go home after its messy wars, our unpopular interventions often helped make life far better for all involved — and the U.S. and its allies more secure.

The United States inherited a mess in the Philippines in 1899 after the defeat of imperial Spain in the Spanish-American war. But after more than a decade of bloody counterinsurgency fighting, America finally birthed a Philippine national government that was given its independence after World War II.

President Harry Truman’s intervention to save South Korea from North Korean aggression quickly turned into a quagmire. Communist China soon launched a massive invasion into the Korean peninsula. By 1953 — at a cost of roughly 35,000 American lives, about eight times more U.S. fatalities than in Iraq — America had at least saved a viable South Korea.

President Dwight Eisenhower, facing re-election in 1956, resisted calls to pull American peacekeepers from the Demilitarized Zone and quit the detested “Truman’s war.”

More than 60 years after the U.S. saved South Korea, thousands of American peacekeepers still help protect a democratic and successful south from a nightmarish, totalitarian and nuclear north.

Some 60 million people died in World War II, a global war that the United States did not start and did not enter until 1941. Yet American power helped defeat the Axis aggressors.

Unlike the aftermath of World War I, the United States stayed on to help rebuild war-torn Europe and Asia after World War II. The Marshall Plan, the NATO alliance, the defeat of Soviet Union in the Cold War, the foundations of the later European Union, and Asian economic dynamism all followed — along with some 70 years of relative peace.

In 1999, President Bill Clinton convinced the NATO alliance to bomb Serbia’s genocidal Slobodan Milosevic out of power and stop the mass killing in the Balkans. After Milosevic’s removal, only the presence of American-led NATO peacekeepers on the ground prevented another round of mass murder.

Donald Trump has rightly reminded us during his campaign that Americans are sick and tired of costly overseas interventions. But what Trump forgets is that too often the world does not always enjoy a clear choice between good and bad, wise and stupid. Often the dilemma is the terrible choice between ignoring mass murderer, as in Rwanda or Syria; bombing and leaving utter chaos, as in Libya; and removing monsters, then enduring the long ordeal of trying to leave something better, as in Afghanistan and Iraq.

The choices are all awful. But the idea that America can bomb a rogue regime, leave and expect something better is pure fantasy.

Victor Davis Hanson is a classicist and historian at the Hoover Institution, Stanford University. Contact him at author@victorhanson.com.